Flash-check for gas-tanks



H. 8. SMITH AND A. F. WESTLUND.

FLASH CHECK FOR GAS TANKS.

APPLICATION FILED 050 23. 1915.

Patented May 6, 1919;

masgzsr ployed, or for some other reason a back flash n STATES PATENT onnicn.

HENRY SIDNEY SMITH AND ALBERT FRANK WESTLUND, 0F INDIANAPOLIS, INDIANA, ASSIG-NORS TO THE PREST-O-LITE COMPANY, INQ, OF INDIANAPOLIS, INDIANA, A

CORPORATION OF NEW YORK.

FLASH-CHECK ron GAS-TANKS.

To all whom it may concern:

Be it known that we, HENRY SIDNEY SMITH, a citizen of Great Britain, residing at Indianapolis, Marion county, and State of Indiana, and AIBERT FRANK WESTLUND, a citizen of the United States, residing at Indianapolis, Marion county, and State of Indiana, have invented and discovered certain new and useful Improvements in Flash- Checks for Gas-Tanks, of which the follow in is a specification. v n the use of acetylene gas when employed as the fuel gas in welding and cutting tools and torches, etc., it is customary to connect a hose to the valve of the tank containing dissolved acetylene direct, or through some regulating device, the, valve being so constructed. as to permit control of-the flow of gas. In such uses, it occasionally occurs,

that because of overheating of the torch emor back fire occurs, this back fire may travel through the length of hose and through the said regulator, and then through the valve,

to the interior of the tank. The violence of the back fire or back flash may result in a local breakin down of the porous filling employed in issolved aceytlene cylinders or tanks thus forming a pocket which, being filled with compressed acetylene gas, may resultin an explosion. In actual practice the pressure in the feed hosemay reach fifteen socket 12 in its top for connection with the I pounds with safetyfprov ided the hose c'ontains only pureacetylenabut if the pressure with the danger of an explosion in the tank exceeds fifteen pounds, or through some reason oxygen or air has become mixed with the acetylene in the hose there is danger of explosion, or decomposition of the gas in the hose, and the said decomposition may travel back through the regulator (if employed) and the valve to the interior of the tank I munication from the hose to the tank immediately on any such back flash or back fire occurring, and thus prevent any of the decomposed gases or fire from entering the tank and therefore guard against thedanger Specification of Letters Patent.' I Patented May 6, 1919; Application filed December 28, 1916. Serial No. 138,659. i

above described, all as will be hereinafter more fully described and claimed.

Referrmg to the accompanying drawings which are made a part hereof, and on which with an outlet fitting or Valve and showing a tube or hose connected therewith, such as s commonly employed to supply tools in the-uses of acetyIene gas such as above re ferred to,

Fig. 2 a central section through the fitting, or valve,

. Fig. 3 a view illustrati the parts com.- posing the flash check in disassembled rela' tion,

Fig. 4 a view of a modified form, and F 5 a view illustrating an arrangementof apparatuswherein a battery of tanks are employed. U 1

In said drawings, the portions marked A represent the acetylene tank, 'and B the tube or hose for making th connection with the cutting, welding, or other tool.

Said tank A is provided with the fitting or valve 10, of a construction best illustrated in Fig. 2. It is formed with a screw-threaded shank 11 adapted to screw into a screwthreaded perforation in a lug formed on the top of the" tank, and has a screw-threaded tube fitting. It is formed with a central aperture 13, which is controlled by a needle 14 mounted in a perforation intersecting said perforation '13 at an angle, as shown. The lower end of the fittinglO is bored out to form a pocket or chamber 15 whichcommunicates at the top with perforation 13 by a similar'perforation 16, forming a continuation thereof. A screw plug 17 of brass or other appropriate material, is mounted in the lower end of socket 15 and is formed with a number of perforations extending there through and establishing communication from the tank to the chamber 15. The upper face of said screw plug 17 is concave, as shown, and a .disk or plate 18, preferably made of lead, or other soft material, is mounted therein. Said disk 18 is formed, with a series of radial hotches spaced around its edge and cutting back an appropriate distance toward its center, through which the gas may pass when fiowin from the tank into the chamber 15. On the top of said disk 18 is mounted a. strainer disk 19, of cloth or fine wire mesh material. On the top of said strainer disk is placed a quantity of lead balls 20, such as ordinary shot. On the top of said balls is placed a series of strainer disks 21 of appropriate material, and on the top of these, another metal disk 22, preferably formed of brass. The screw plug 17 is also preferably formed of brass.

n assembling, of course, the fitting is turned upside down and the parts put in place in the reverse order of that just stated. The perforated plate 22 and the mesh strainer cloths 21 and 19, and the notched lead plate 18, form a type of filter through which the gas passes and is broken up and its force or pressure somewhat retarded in its passage from the tank to the tube B, but not sufliciently to interfere with the practical and efficient feed of the gas to the work. In the event of a back flash, the pressure upon the washer 15 and strainer cloths, transmitted by the shot against the center of the lead disk 18, causes said disk to buckle down onto the concave top face of the screw plug 17 and close the perforations therein; and at the same time, may cause said lead shot, and possibly the lead disk, to melt or fuse somewhat andform an effectual check at this point to an back flow of the gases or fire into the tan thus safeguarding the contents of the tank and avoiding the danger of an explosion.

The construction in Fig. 4: will be readily understood "from the foregoing description, it being merely a different type of fitting adapted to be inserted at any desired point in the supply line, instead of being formed in the body of the valve itself.

In Fig. 5 we show a battery of gas tanks, and any number may be used instead of the two shown, each tank connected to a header 25, from which the supply tubex26 leads to the tool. A flash checkof our improved construction may be provided in the outlet fitting or valve of each tank, and, if desired, fittings of the form shown in Fig. 4 may be provided at points 27, where the cylinders connect into the manifold, or at any other points in the sulgply line at which it is desired to arrest a ash or fire back.

Having thus fully described our said invention, what we claim as new and desire to secure by Letters Patent, is:

1. A flash check for acetylene gas supply line comprising a casing, a chamber in said casing, apertures leading to and from said.

chamber, a soft plate mounted in spaced relation fror'n the bottom of said chamber and a fusible material mounted on said plate and adapted to transmit the pressure caused by back firto the plate and thereby-cause the same to close the apertures, substantially as set forth.

2. A fitting for acetylene gas supply line comprising a member having an aperture therethrough, avalve for controlling said aperture, said aperture having an enlarged chamber with perforations leading thereinto from the tank and therefrom to the discharge, the floor of said chamber being formed concave and having a plate of comparatively soft material mounted therein, and means mounted on said plate for transmitting the pressure caused by back fire to force said plate to close the apertures and prevent communication with the tank, substantially as set forth.

3. The combination with an acetylene gas tank, of an outlet fitting havingan aperture through which the gasmay pass from the tank to the point of use, said aperture having an enlarged chamber, and means mounted in said chamber through which the gas may pass under normal conditions but which under sudden extraordinary pressure or temperature will compact over and close the outlet aperture from the tank, substantially as set forth.

1. The combination with an acetylene gas tank, a supply line leading therefrom, having a fitting formed with an outlet aperture having an enlarged chamber extending be yond the edges of the normal aperture,and a filling in said chamber through which the gas may pass under normal conditions but which will compact and fuse under extraordinary pressure or temperature'to close said aperture, substantially as set forth 5. A fitting for the supply lines of gas tanks having an aperture formed with an enlarged chamber of larger diameter than the normal aperture and with a concave floor, a disk of soft material mounted above said floor with apertures'around its edges larged chamber containing a soft disk cov-' ering the aperture and aving openings to one side of said apertur through which the gas may pass, and means above said disk for transmitting pressure caused byback fire, to compress said disk and close the aperture, substantially as set.forth.

7. A fitting for the supply lines of gas tanks having an aperture formed "with" an enlarged chamber a soft disk in said chamber covering said aperture and formed to permit the passage of the gas to the side of said aperture, and material adapted to flow .130

under high pressure and fuse under high temperature mounted above said disk to receive any back'pressure caused by back fire from the point of use, substantially as set forth.

8.- The combination with an acetylene gas tank, of an outlet fitting having an aperture through which the gas may pass from the tank to the point of use, said aperture having an enlarged chamber, and means mounted in said chamber through which gas may pass under normal conditions but which under a fusion temperature will fuse over and close the outlet aperture from the tank, substantially at set forth. 5

9. An explosion arrester for gasburning apparatus comprising a gas conduit, means for supporting within said conduit a quantity of material which is fusible at the temperature of a gas flame, means'for retarding the movement of a flame through said conduit in the neighborhood of and in good thermal relation to said material, and means located in the" gas conduit for receiving said material when fused to seal said conduit.

10. The method of arresting the progress of an explosion through a gas conduit which consists in arranging in thermal relation to a flame in said gas a quantity of material which is fusible at the temperature of said HENRY SIDNEY siiirli. 1,. 8-] ALBERT FRANK WEVS'ELUND. [a 3.

Witnesses:

. JOHN H. ALTER, H. L. GOULD. 

